Claude Parallel Tasks MCP Server

Instructions

Implementation Reference

• src/index.ts:36-106 (handler)

  Handler function that maps over queries, executes each Claude task via shell command using claude CLI in parallel with Promise.all, generates output files, and returns a summary report.
  async ({ queries }) => { const taskPromises = queries.map(async (query, i) => { const { queryText, contextFilePaths } = query; // Escape double quotes in the query to prevent command injection issues const escapedQueryText = queryText.replace(/"/g, '\\"'); const outputFileName = `claude_task_${i}_${Date.now()}.md`; let fileContextString = ""; if (contextFilePaths && contextFilePaths.length > 0) { // Ensure file paths are properly escaped if they contain spaces or special characters // For simplicity, assuming paths don't need complex escaping beyond being quoted if necessary. // However, for robust handling, each path might need individual shell argument escaping. fileContextString = contextFilePaths.map((fp) => `"${fp}"`).join(" ") + " "; // Add a space after the files } // Use environment variable for API key const apiKey = process.env.ANTHROPIC_API_KEY; if (!apiKey) { throw new Error("ANTHROPIC_API_KEY environment variable is not set"); } const command = `export ANTHROPIC_API_KEY=${apiKey} && claude -p --dangerously-skip-permissions ${fileContextString}"${escapedQueryText}" > ${outputFileName} 2>&1`; try { const { stdout, stderr } = await execAsync(command); return { query: queryText, command: command, outputFile: outputFileName, status: "completed", stdout: stdout, stderr: stderr, }; } catch (error) { const err = error as Error; return { query: queryText, command: command, outputFile: outputFileName, status: "failed", error: err.message, }; } }); // Wait for all tasks to complete const taskExecutionResults = await Promise.all(taskPromises); const reportLines = taskExecutionResults.map( (r) => `Task for query (first 30 chars): "${r.query.substring( 0, 30 )}..." - Status: ${r.status}. Output file: ${r.outputFile}${ r.error ? ` (Error: ${r.error})` : "" }` ); return { content: [ { type: "text", text: `Completed ${ queries.length } Claude tasks in parallel.\\nDetails:\\n${reportLines.join("\\n")}`, }, ], }; }
• src/index.ts:22-35 (schema)

  Zod schema defining the input parameter 'queries' as an array of objects with queryText (string) and optional contextFilePaths (array of strings).
  queries: z .array( z.object({ queryText: z.string().describe("The text prompt to send to Claude"), contextFilePaths: z .array(z.string()) .optional() .describe( "Optional list of file paths to provide as context to Claude" ), }) ) .describe("A list of query objects to run with Claude in parallel"), },
• src/index.ts:18-107 (registration)

  MCP server tool registration call including name, description, input schema, and inline handler function.
  server.tool( "run_parallel_claude_tasks", "Runs multiple Claude prompts in parallel, optionally with file contexts, redirecting output to files.", { queries: z .array( z.object({ queryText: z.string().describe("The text prompt to send to Claude"), contextFilePaths: z .array(z.string()) .optional() .describe( "Optional list of file paths to provide as context to Claude" ), }) ) .describe("A list of query objects to run with Claude in parallel"), }, async ({ queries }) => { const taskPromises = queries.map(async (query, i) => { const { queryText, contextFilePaths } = query; // Escape double quotes in the query to prevent command injection issues const escapedQueryText = queryText.replace(/"/g, '\\"'); const outputFileName = `claude_task_${i}_${Date.now()}.md`; let fileContextString = ""; if (contextFilePaths && contextFilePaths.length > 0) { // Ensure file paths are properly escaped if they contain spaces or special characters // For simplicity, assuming paths don't need complex escaping beyond being quoted if necessary. // However, for robust handling, each path might need individual shell argument escaping. fileContextString = contextFilePaths.map((fp) => `"${fp}"`).join(" ") + " "; // Add a space after the files } // Use environment variable for API key const apiKey = process.env.ANTHROPIC_API_KEY; if (!apiKey) { throw new Error("ANTHROPIC_API_KEY environment variable is not set"); } const command = `export ANTHROPIC_API_KEY=${apiKey} && claude -p --dangerously-skip-permissions ${fileContextString}"${escapedQueryText}" > ${outputFileName} 2>&1`; try { const { stdout, stderr } = await execAsync(command); return { query: queryText, command: command, outputFile: outputFileName, status: "completed", stdout: stdout, stderr: stderr, }; } catch (error) { const err = error as Error; return { query: queryText, command: command, outputFile: outputFileName, status: "failed", error: err.message, }; } }); // Wait for all tasks to complete const taskExecutionResults = await Promise.all(taskPromises); const reportLines = taskExecutionResults.map( (r) => `Task for query (first 30 chars): "${r.query.substring( 0, 30 )}..." - Status: ${r.status}. Output file: ${r.outputFile}${ r.error ? ` (Error: ${r.error})` : "" }` ); return { content: [ { type: "text", text: `Completed ${ queries.length } Claude tasks in parallel.\\nDetails:\\n${reportLines.join("\\n")}`, }, ], }; } );